The high-frequency conductivity tensor of two-dimensional electron gas with impurity states of electrons in a magnetic field

I.M.Lifshitz's method of local perturbations is used to study the properties of a two-dimensional electron-impurity system in a quantizing magnetic field perpendicular to the plane of electron motion. The tensor of the high-frequency conductivity of the system is calculated within the model of independent impurity point atoms taking into account the impurity states of the electrons and the spatial dispersion. The dissipative part of the conductivity has narrow maxima at the frequencies of the electron transitions between the Landau levels and local levels induced by the electromagnetic field. In the absence of a magnetic field the maxima merge producing a wide maximum which is above the threshold frequency of the electron transitions from the local levels to the band. The maxima are calculated numerically for semiconductor structures with two-dimensional electron gas